Moscow, July 28 : The two Russian submersibles which dived to the sea-bed beneath the North Pole last year are now attempting to reach the bottom of Lake Baikal in Siberia, which is the world's deepest lake.

Lake Baikal is estimated to be 25 million years old. It contains around 23,000 cubic metres of fresh water - about 20 per cent of the world's fresh water and 90 per cent of Russia's.

The majority of flora and fauna of the lake are unique to the area.

According to a report in Russia Today, the submersibles, known as Mir One and Mir Two, will try to measure the maximum depth of the lake.

Scientists intend to go as deep as 1,700 metres to study the tectonics of Lake Baikal and to inspect archaeological artefacts.

Research work on the bottom of the lake is scheduled to begin on July 29.

The operation, which will last till mid-September, will also provide data for geological, chemical and biological studies.